How to access and read a file on a USB drive from IOS Connected via OTG cable to iPhone

Question

Can I parse a file (access a text file and read contents) on a USB drive from IOS? (Eg OTG cable to iPhone). Is USB device that mounts as file system normally, e.g. on MacBook

Which library/framework to use?

Or is it possible from iPad if not from iPhone?

Clarification: If there is a test.txt file on the USB drive, then ability to open it from iPhone IOS app (assuming connected via OTG cable) read only, then read the contents as a string. Or open for reading as text file and read line by line.